Meningococcemia (cont.)

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

What are risk factors for meningococcemia?

Children and adolescents 5 to 19 years of age are at highest risk for
meningococcemia. Newborns acquire antibodies from their mothers via
the placenta, although these antibodies fade after a few weeks or months.
Toddlers are not immune, and there have been several exposures in day-care
settings. As children age, they gradually gain immunity to meningococcal
strains by coming into contact with milder strains of the bacteria.
However, because this immunity is imperfect, it is still possible for adults to
get meningococcemia.

The immune system is critical in fighting off the bacteria.
Patients who have a history of a specific genetic deficiency in the complement
system are at high risk for severe disease. The spleen is also needed for
an effective immune response, so people are at higher risk for severe disease if
they have had their spleens taken out or have spleens that function poorly.

People who have been in close contact with an infected patient are at increased risk to acquire the disease themselves. People who live together in close quarters such as military barracks are at special risk for disease, because one infected person can spread the disease to many others. One study showed that the attack rate in household contacts was 500 times greater than that of the general population.

In some parts of the world, outbreaks of meningococcal disease occur regularly. This is true of a group of countries in sub-Saharan Africa, which is known as the "meningitis belt." Because travelers from this area visit Saudi Arabia during the Hajj, there have been outbreaks associated with the pilgrimage. Saudi Arabia now requires proof of meningococcal vaccination before admitting pilgrims. Prevention of similar outbreaks is possible; for example, many
universities in the U.S. now require proof of meningococcal vaccination before the students can attend classes.